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Your search keyword '"Ponezha, E. A."' showing total 17 results
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17 results on '"Ponezha, E. A."'

1. Electron transport through degenerate electron level in single-molecular junction in the presence of electron-vibrational coupling and attractive electron-electron correlations.

Author

Ponezha, E. A.

Subjects
*ELECTRON transport, *ELECTRON-electron interactions, *ELECTRON configuration, *ELECTRON tunneling, *ELECTRONS, *SINGLE molecules
Abstract

Electron transport through a molecular junction consisted of a single molecule coupled to macroscopic leads is studied in the nonequilibrium regime. The molecule is modeled as a degenerate energy level with an electron-vibrational interaction and attractive electron-electron correlation which lifts the degeneracy. The level occupancy and differential conductance are calculated in the antiadiabatic regime with an account of molecule-lead coupling at low temperature and finite voltage. The method of transport spectroscopy made it possible to determine through which of the split levels tunneling takes place depending on the applied voltages and to estimate the current through these levels. The cases of a negative differential conductance are discussed. The influence of the electron-vibrational coupling of different strength on electron tunneling through 2- and 4-fold degenerate level on the molecule in the presence of the attractive electron-electron interaction is analyzed. [ABSTRACT FROM AUTHOR]

Published
2024
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5. Часи релаксацiї та кореляцiйнi функцiї пiд впливом крос-корельованих шумiв у моделi резонансного тунелювання

Author

Ponezha, E. A.

Subjects
associated relaxation time, strength of cross-correlation, external colored noises, intensity correlation function, resonant tunneling
Abstract

The effects of cross-correlated noises on the process of relaxation of fluctuations in the model of resonant tunneling, in which the noise sources due to incident flow intensity fluctuations and frequency fluctuations are assumed to exist, are considered. To characterize the dynamical behavior of the system, the normalized correlation functions and the associated relaxation times are calculated with the help of a projection-operator technique with regard for memory effects. The influence of noise intensities, their correlation times, and the strength of correlation between the noises on these functions has been analyzed. It is found that the strength of a cross-correlation between two noises can facilitate the intensity fluctuation decay. The behavior of the relaxation time with respect to that of the strength of noises can be characterized as a stochastic resonance phenomenon. It is shown that an enhancement of the self-correlation time of the intensity fluctuations accelerates the transition from the unstable state, while the growth of the self-correlation time of frequency fluctuations results in the retardation of the transition, thereby stabilizing the system., Розглянуто вплив крос-корельованих шумiв на процес релаксацiї флуктуацiй у моделi резонансного тунелювання, в якiй передбачалась наявнiсть джерел шумiв, пов’язаних з флуктуацiями iнтенсивностi та частоти в падаючому потоцi. Для характеристики динамiчної поведiнки системи розраховувалися нормованi функцiї кореляцiї i асоцiйованi часи релаксацiї за допомогою методу проекцiйного оператора з урахуванням ефектiв пам’ятi. Проаналiзовано вплив на цi функцiї iнтенсивностей шумiв, їх часiв кореляцiї, а також сили взаємної кореляцiї i часу крос-кореляцiї. Було знайдено, що сила кореляцiї мiж двома шумами може прискорити розпад флуктуацiй iнтенсивностi. Залежнiсть часу релаксацiї вiд iнтенсивностi шумiв може бути охарактеризована як стохастичний резонанс. Було показано, що збiльшення часу кореляцiї флуктуацiй iнтенсивностi прискорює перехiд з нестабiльного стану, у той час як рiст часу кореляцiї флуктуацiй частоти затримує перехiд, тим самим збiльшуючи стабiльнiсть системи.

Published
2019
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8. Modelling of Cold Electron Filtration in Tunnelling Nanostructures with Metallic Quantum Dot.

Author

Ermakov, V. N. and Ponezha, E. A.

Subjects
QUANTUM dots, ELECTRON-phonon interactions, THERMAL electrons, QUANTUM wells, TUNNELS, RESONANT tunneling, POLARONS
Abstract

The microscopic model of suppressing thermal smearing of electrons in resonant tunnelling structures with nonlinearity due to electron-phonon interaction under the assumption of the presence of degenerate levels in the quantum well is proposed. The electron-phonon interaction results in an effective attraction with breaking the degeneracy and lowing the energy level. We note the manifestation in this model of the Fano effect associated with multichannel tunnelling. As an example, the effect of suppressing the thermal spread of electrons in a nanotransistor with a metal quantum dot is considered and compared with the experiment. A rather significant (about 200 K) heating of the quantum dot was detected caused by the passage of a current through the nanotransistor. Despite heating, the effect of cold electrons filtration is clearly observed. The theory and experiment were found to be in a good agreement. [ABSTRACT FROM AUTHOR]

Published
2020
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